Controlled pullup gageable preswage tool

ABSTRACT

A manual pre-swage tool is particularly useful for pre-setting the tube fitting ferrules onto the tube prior to the actual installation of the fitting components into the tube fitting body. The pre-swage tool is used by clamping in a vise, or other suitable means, in an open area where leverage and ease of use can be obtained. This new and improved design tool of the present disclosure incorporates a feature that prevents the ferrules from being over tightened thereby preventing damage to the tool or ferrules and also allowing the pre-swaged assembly to be fully compatible with what is called “stop collars” and “gap inspection gages” that are commonly used in the field to indicate proper pull up of the tube fitting when installed.

BACKGROUND

This application claims the priority benefit of U.S. provisional application Ser. No. 62/409,915, filed Oct. 19, 2016, the entire disclosure of which is expressly incorporated herein by reference.

This disclosure pertains to the use of a pre-swaging tool. More particularly, the invention pertains to a pre-swaging tool that pre-swages instrument-type tube fitting ferrules on to a tubing (tube) in an open, easily accessible area where leverage can be obtained to ease the force of pre-swaging the tube fitting ferrules onto the tubing and rotation of the wrench to tighten the nut is not hindered in any way.

Many of these types of fittings are installed in tight, cramped quarters. The tight quarters limit the turning of the tube fitting nut to small increments of tightening and also make it hard to develop the torque required to tighten the tube fitting nut.

These types of tools are in wide use but all of the current designs have serious drawbacks for the tool and also for the integrity of the tube fitting installation itself. The current designs that are used can allow the end user to over-tighten the tube fitting nut to an extent that can damage the tool and shorten it's useable tool life but more importantly, the over-tightening that is possible with the current design that is in use can make the reassembly of the pre-swaged ferrules into the tube fitting body to not be compatible with “stop collars” or “gap gages” which are both widely used in the industry.

Over-tightening the fitting nut on the currently available pre-swage tool can have several potential adverse or detrimental effects. For example, over-tightening the fitting nut can prevent the proper remake of the pre-swaged ferrules into the body when a “stop collar” is used which can potentially result in some cases with a high pressure gas leak. The stop collar can indicate a proper pull up when in fact the tube fitting was not remade properly after using the pre-swage tool.

It can also adversely affect the number of remakes that the pre-swaged ferrule assembly can have when installed into the fitting body when gap gages are not used.

SUMMARY

A need exists for an improved arrangement that overcomes one or more of the above-noted problems.

Benefits and advantages of the present disclosure will become more apparent from reading and understanding the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are a perspective view and a cross-sectional view, respectively, of a conventional style manual pre-swage tool in current use.

FIG. 2 is a longitudinal cross-sectional view of a first embodiment (pressed-on stationary collar) of a pre-swage tool of the present disclosure.

FIG. 3 is a perspective view of the pre-swage tool of FIG. 2 (with the nut and ferrules removed for ease of illustration).

FIG. 4 is a longitudinal cross-sectional view of a second embodiment (internal press-fit body die) of a pre-swage tool of the present disclosure.

FIG. 5 is a perspective view of the pre-swage tool of FIG. 4 (with the nut and ferrules removed).

FIG. 6 is a longitudinal cross-sectional view of a third embodiment (rotatable collar) of a pre-swage tool of the present disclosure.

FIG. 7 is a perspective view of the pre-swage tool of FIG. 6 (with the nut and ferrules removed).

FIG. 8 is an exploded, perspective view of another modified pre-swage tool.

DETAILED DESCRIPTION

In FIGS. 1A and 1B, a manual pre-swage tool 100 in current use is shown having a body or housing 102 that includes a proximal, first end 104 and a distal, second end 106 spaced along a longitudinal axis from the first end. The first end 104 includes a reduced dimension portion 108 that is externally threaded at 110. The reduced dimension portion 108 further includes an internal recess 112 dimensioned to receive a terminal end of a conventional, hollow tube or tubing T. In a manner well known in the art, a fitting 130 includes an internally threaded nut 132 and first and second ferrules 134, 136. The components 132, 134, 136 of the fitting 130 are illustrated in FIGS. 1A, 1B prior to pull up as noted in the Background. The fitting is conventional in the art and details of the structure and operation/function of the nut 132 and first and second ferrules 134, 136 are well known to those skilled in the art so that further detailed description is unnecessary to a full and complete understanding of the present disclosure. During a pre-swage operation, the nut 132 and ferrules 134, 136 are positioned over the end of the tubing T, the tubing and advanced into the recess 112 of the first end 104 of the body 102, and the nut is advanced by rotating the nut relative to the body 102, i.e., along the external threads 110, by a predetermined amount. This pre-swages or makes-up the fitting 130 whereby the first and second ferrules 134, 136 are deformed into gripping engagement with the external surface of the tubing T, and likewise the external surface of the tubing is deformed as the ferrules are driven into tight gripping, sealing engagement therewith. For example, a recommended 1¼ turns past finger tight (or slightly less for a pre-swage) of the nut 132 relative to the body 102 results in proper pre-swage make-up of the assembly.

As also shown in FIGS. 1A-1B, a protective cap, closure, or cover C may also be provided with the conventional pre-swage tool 100 to protect the external threads 110 of the reduced dimension portion 108 of the body 102. A retainer R such as a chain or strap joins the cover C to the body if so desired. During the pre-swage operation, the cover C is removed and the above-described pre-swage operation is undertaken. In addition, tool engaging surfaces or tool flats 140 are typically provided on the body to facilitate engagement by an associated tool (not shown) and stabilize the housing during make-up of the fitting 130, or loosening of the nut 132 (which also has tool engaging surfaces or tools flats thereon) once the pre-swage operation is complete. Once the nut 132 is loosened from make-up, the terminal end of the tubing T is removed from the housing recess 112 with the nut 132 and ferrules 134, 136 still held on the end of the tubing.

FIGS. 2 and 3 show a first embodiment of the present disclosure of a controlled pull up, pre-swage tool 200. Where possible, like reference numerals in the “200” series will be used in order to reference like components, and new reference numerals will identify new components, to facilitate understanding of the present disclosure. For example, housing/body 202 in FIGS. 2-3 bears some similarities to housing/body 102 in FIG. 1. The body 202 includes a first end 204 having a reduced dimension portion 208 that is externally threaded as shown at 210. The first end 204 of the body 202 is modified to include a pressed on pullup limiting collar 240 that is permanently mounted on the body but can freely rotate relative to the body until proper pull-up is completed. That is, the nut 232 is axially advanced relative to the body 202 by rotating the nut on the external threaded portion 210. Again the ferrules 234, 236 are deformed into gripping, sealing engagement with the external surface of the tubing (not shown for ease of illustration) received in the recess 212. The axial advancement of the nut 232 is limited by abutment between an inner, end face 242 of the nut with surface 244 of the collar 240. Thus, the initial gap 246 between the surfaces 242, 244 is over, during the pre-swage or pull-up of the nut on to the housing. The gap 246 is carefully controlled and defined as the distance that the nut 232 travels on the external threads 210 of the body 200 (e.g., that axial dimension associated with 1¼ turns past finger tight). The benefit offered by the use of the rotating collar 240 is that an additional feedback of proper pull-up is provided to the user i.e., the nut 232 can be tightened until such time as abutment occurs between the faces 242, 244 and the torque dramatically increases in an effort to further tightening the nut on the body 202. This provides a positive feedback to the user/installer that the nut 232 has been properly installed on the body 202. As will be appreciated, this is a significant improvement in those instances where the fitting 230 is ultimately used in tight, cramped quarters.

Those familiar with the current pre-swage tool designs will appreciate the fact that with this new and improved design (any one of the embodiments of FIGS. 2-7), the end user does not have to carefully make a mark on the nut and tighten the nut to the prescribed pull up which is typically 1¼ turns past finger tight. The end user simply has to tighten the nut on the pre-swage tool until the nut cannot be tightened any further. This is easily determined by the sudden increase in torque that prohibits any further tightening of the nut.

The design can, as also shown, have a collar (similar in appearance to the stop collars used on the tube fitting assembly) that is permanently mounted but freely rotates until the proper pull up is achieved. This additional feature gives an additional fail safe against improper pull up (under-tightening) of the tube fitting components.

The precise configuration of the interface between the collar 240 and the body 202 may be altered in practice, although the illustrated preferred arrangement provides a radial shoulder 250 on the body 202 that cooperates with shoulder 252 that extends in an axial direction from the collar toward the radial shoulder (i.e., at an opposite end of the collar from surface 244). In a conventional pre-swage tool, the nut 132 can be over tightened as a result of the advancement of the nut relative to the body. In the present disclosure, this potential for over tightening cannot occur as a result of the abutment of the nut with the collar 244.

Installing the pre-swaged assembly into the tube fitting body is then accomplished the same as the current practice, i.e., tighten until an increase in torque is noted, then snug approximately ¼ turn, or until the nut abuts the “stop collar” when used. The pull up in the tube fitting body can also be checked for proper assembly using the “Gap Inspection Gage” when stop collars are not used and inspection for proper assembly is required.

This new and improved design which prevents over tightening of the nut can significantly reduce pull up errors in the pre-swaging operation and also significantly increase the useful life of the pre-swage tool itself. The added feature of the rotating collar will also help to reduce under-tightening which could lead to catastrophic failure of the tube fitting's holding ability.

According to the present disclosure, a new and improved manual pre-swage tool for use with the instrument type tube fitting is provided. The present disclosure changes the current design that all the major tube fitting manufacturers are currently selling to a tool that limits the maximum pull up that can be done to a predetermined amount. The currently available pre-swage tools are identical to the tube fitting which means that the user can over tighten the tube fitting components by any amount that they want. With the present disclosure, the possibility of over tightening is eliminated by physically making this impossible.

An alternative embodiment is shown FIGS. 4-5. Again, for ease of illustration and understanding, like reference numerals in the “400” series will refer to like components (e.g., the new pre-swage tool 400 bears some similarities to the pre-swage tool 100 of the prior art, or the new pre-swage tool 200 of FIGS. 2-3). In the arrangement of FIGS. 4-5, the pre-swage tool body 402 is modified to have an enlarged cavity 460 that extends therethrough, and dimensioned to receive a pressed in body die 470. More particularly, the body die 470 includes a shoulder 472 that abuts with inwardly extending shoulder 474 of the body and prevents the die from advancing through opening 476 at the first (proximal) end 404 of the body. The body die 470 is pressed in place and includes an external thread portion 410 that receives the nut 432. Again, the nut 432 and ferrules 434, 436 are placed over the terminal end of the tubing (not shown) and then the tubing is inserted into the recess 412 of the pre-swage tool 400. The nut 432 is then rotated to be finger tight on the threads 410 of the body die 470 which establishes an initial dimensional 446 gap (FIG. 4) between end face 442 of the nut and surface 444 of the body 402. The customer then stabilizes the pre-swage tool 400 via the tool flats 440 and rotates the nut 432 past finger tight until the torque dramatically increases upon abutment between nut surface 442 and body surface 444. This will occur at approximately 1¼ turns, although the customer need not measure the exact number of turns since the increased torque will provide positive feedback that the pre-swage is complete and proper pull up is achieved.

Still further, FIGS. 6-7 show another embodiment. This embodiment may be a more desirable way to do accomplish the pre-swage and has an advantage over the first preferred method. For ease of illustration and understanding, like reference numerals in the “600” series will refer to like components (e.g., the new pre-swage tool 600 of FIGS. 6-7 bears some similarities to the pre-swage tool 100 of the prior art, the new pre-swage tool 200 of FIGS. 2-3, and the new pre-swage tool 400 of FIGS. 4-5).

More specifically, the pre-swage tool 600 has a body or housing 602 with a proximal, first end 604 and a distal, second end 606. A reduced dimension portion 608 includes an external threaded portion 610 and recess 612 is dimensioned to receive tubing (not shown for ease of illustration) therein. Nut 632 of the fitting 630 is received on the tubing, namely over the terminal end thereof, with the first and second ferrules 634, 636 received within the nut and on the external surface of the tubing. When the nut 632 is brought to finger tight engagement with the threaded portion 610 of the body, a predetermined gap 646 is defined between end face 642 of the nut and surface 644 of the collar 640. Rather than being press fit on to the body, the collar 640 is secured thereto by at least one retaining pin 680, and preferably multiple pins are generally equally-spaced about the perimeter of the collar for receipt in annulus 682 of the body. Further, bearings or seals 684 are provided at the axial interface between the collar 640 and the body 602 to allow relative rotation.

This variation of FIGS. 6-7 has a physical stop (collar 640) that limits the pull up to the desired amount but this design allows the physical stop or collar to rotate if the pull up is under-tightened. This design gives the user/customer two ways to tell if the tube fitting components have been properly pre-swaged. One is by the sudden and irresistible force that is felt when the tube fitting nut 632 abuts the physical stop collar 640 and the other is that the physical stop collar cannot be rotated once the tube fitting nut abuts it. This additional feature resembles what is currently available for use on the tube fitting itself when a customer does not use a pre-swage tool. It is believed that this additional feature would be very popular since it mimics the stop collars used on the fitting bodies to show proper pull up.

FIG. 8 is a still additional embodiment. As shown, FIG. 8 illustrates a tool where the body die is a hex and installed from the top and can easily be replaced by the customer or factory representative. This is in contrast to the embodiment of FIG. 4 where the die is pressed in from the bottom and generally not deemed to be replaceable. With the arrangement of FIG. 8, however, modifications show how the body is divided into two components. Once again, for ease of illustration and understanding, like reference numerals in the “800” series will refer to like components in an effort to provide a general correlation to the new embodiment.

The pre-swage tool 800 has a body or housing 802 with a proximal, first end 804 and a distal, second end 806. As is evident in FIG. 8, reduced dimension portion 808 is a separate component from a remainder of the housing 802. One end of the reduced dimension portion 808 includes, for example, a hex perimeter 890 dimensioned for receipt in hex opening 892 in the first end 804 of the body 802. This hex arrangement (or other configuration) prevents relative rotation between the components when the hex perimeter 890 is received within the hex opening 892. Further, this arrangement advantageously allows the reduced dimension portion 808 that includes the external threads 810 (that cooperates with the internal threads on nut 832) to be replaced/substituted if so desired. Thus, the tubing (not shown for ease of illustration) is still received through the opening in the nut 832 and ferrules (not shown), and the terminal end of the tubing inserted into the recess 812 whereby the internal threads of the nut cooperate with the external threads 810 for pre-swaging of the assembly. When assembled, one will appreciate that the tool 800 looks similar to that illustrated in FIG. 7 but with the distinct difference that the body 802 and the reduced dimension portion 808 are separate components that are assembled together in the embodiment of FIG. 8. Pin 880 is received radially through the collar 840 for receipt in annulus 882 of the body to axially interconnect the body 802 and collar while allowing selective rotation therebetween. Again, the user/customer has two ways to determine if the tube fitting components have been properly pre-swaged. One is by the sudden irresistible force that is encountered when the tube fitting nut 832 abuts the physical stop collar 840 (engagement of respective faces 842, 844), and the other is the physical stop collar 840 cannot be rotated once the tube fitting nut 832 abuts it. The ability to replace or substitute the reduced dimension portion 808 in the embodiment of FIG. 8 allows for the pre-swage tool 800 to be used with different sized fittings.

By controlling the pull up on the pre-swage tool to the required amount, all pull ups done using the new design pre-swage tool can now be compatible with the stop collars and gap type gages that are used to verify proper pull up in the final assembly.

It is also noted that the customer cannot use any of the manual pre-swage tools that are currently available if the customer intends to use any type of stop collar or gap gage to verify final assembly. This is due to the fact the user can over tighten the tube fitting components using the pre-swage tool which makes the use of stop collars or gap gages useless.

In accordance with the present invention, a manual pre-swage tool is shown that facilitates the proper pre-swaging of the tube fitting components by limiting the amount of pull up to what is required.

According to the invention, the amount of pre-swage done to the tube fitting ferrules is limited to the proper recommendation of 1¼ turns past the finger tight position, (or slightly biased just short of the recommended pull up) and makes the pre-swaged assembly compatible with all current types of installation requirements.

This includes systems that use what is commonly called “stop collars” which limit the pull up in the fitting body when a pre-swage tool is not used along with installations that require the tube fitting pull up to be verified by what is called a “gap inspection gage”.

Thus, the nut and ferrules are received over the terminal end of the tubing prior to inserting the terminal end of tubing into the recess of the pre-swage tool. The nut is initially finger tightened. Subsequently, a tool such as a wrench is used to tighten the nut the desired amount (1¼ turns), but more assuredly until the torque dramatically increases when the nut engages the body (e.g., collar surface). The nut is subsequently loosed by counter-rotation of the nut, and the tube can thereby be removed from the pre-swage tool. As a result, the tubing, nut, and ferrules are now ready for proper installation in the fitting.

This written description uses examples to describe the disclosure, including the best mode, and also to enable any person skilled in the art to make and use the disclosure. Other examples that occur to those skilled in the art are intended to be within the scope of the invention if they have structural elements that do not differ from the same concept, or if they include equivalent structural elements with insubstantial differences. 

I claim:
 1. A controlled pullup gageable preswage tool for use with an associated fitting assembly that includes an associated nut, at least one associated ferrule, and an associated tube, the preswage tool comprising: a first body including a first, proximal end and a distal, second end spaced therefrom along a longitudinal body axis, the first body member including a first, engaging surface, and further including first and second tool flats disposed on an external surface thereof; a second body member having a proximal, first end and a distal, second end spaced therefrom, the second body member mounted to the first body member for selective rotation relative thereto, the second body member including a second, engaging surface that is disposed in facing relation with the first, engaging surface of the first body member and able to move relative thereto when an axial load is less than a predetermined level, and the first, engaging surface does not move relative to the second, engaging surface of the second body member when the axial load applied to the first and second bodies exceeds the predetermined level, and an externally threaded region extending from the first, proximal end of one of the first and second bodies, the externally threaded region dimensioned for threaded engagement with the associated nut surrounding a recess in the first, proximal end of the one of the first and second bodies, and dimensioned to receive an end portion of the associated tube.
 2. The preswage tool of claim 1 wherein the axial load applied to the first and second body members advances the body members toward one another.
 3. The preswage tool of claim 1 wherein the externally threaded region extends from the proximal end of the first body, and the second body is an annular collar received around the first body.
 4. The preswage tool of claim 1 wherein the externally threaded region extends from the proximal end of the second body, and the second body is received in a cavity formed in first body.
 5. The preswage tool of claim 4 wherein the first body includes a shoulder and the second body includes a shoulder disposed in facing relation to one another, and defining an extent by which the externally threaded region of the second body extends outwardly from the first body.
 6. The preswage tool of claim 4 further comprising at least one retaining member joining the first and second bodies together.
 7. The preswage tool of claim 4 further comprising at least first and second retaining pins radially interconnecting the first and second bodies together.
 8. The preswage tool of claim 7 wherein the retaining pins are equi-spaced around the first and second bodies.
 9. A method of preswaging ferrules received in a nut on a tube, the method comprising: providing a preswage tool that includes first and second bodies that selectively rotate relative to one another, providing an externally threaded region on one of the first and second bodies; placing the ferrules and nut on the tube; and subsequently threadedly advancing the nut on the externally threaded region until the first and second bodies of the preswage tool no longer rotate relative to one another.
 10. The method of claim 9 further comprising advancing the nut on the externally threaded region until the torque required for make-up rapidly increases.
 11. The method of claim 9 further comprising providing the externally threaded region on the first body.
 12. The method of claim 11 wherein the second body is a collar rotatably received over the first body at an end thereof adjacent the nut, tube and ferrules.
 13. The method of claim 12 further comprising providing a recess in the first body that receives a terminal end of the tube.
 14. The method of claim 9 further comprising providing the externally threaded region on the second body where the second body is partially received in a cavity of the first body.
 15. The method of claim 9 further comprising retaining the first and second bodies together with frangible pins.
 16. The method of claim 15 further comprising situating a seal between the first and second bodies.
 17. The method of claim 9 further comprising loosening the nut from the externally threaded region after the first and second bodies of the preswage tool no longer rotate relative to one another.
 18. The method of claim 17 further comprising removing the tube from a recess of the preswage tool. 